Re: [CAD_CAM_EDM_DRO] Poll: All the missing step hype

In a message dated 14-Jun-02 15:33:35 Central Daylight Time,
indigo_red@... writes:

> Could you please take a second
> and comment on how well your stepper system is or is not working.
>
> I've got G210's and plan on using full or half steps.

Lee: I built two application-specific "CNC" lathes using the new Superior
Electric KML-092 bipolar motors, driven by THEIR dual-drive+power-supply
(overpriced) box. I have mucho experience with "unipolar 6-wire" steppers
before that.

The recent S.E. driver product and these relatively-new steppers they now
make are VASTLY superior to the old "unipolar" motors! And the new drives
have opto-isolator inputs, and this arrangement ELIMINATES any "phantom
steps" or "missing steps" as showed up, now and then, with the old unipolar
system when, for example, someone would turn on-or-off another motor in the
same shop.

I have recently bought a pair of G210's and two S.E. KML-062 motors (much
smaller!) with which I will be building another plotter for tracing the
"lathe program moves". I have so far only hooked up the G210's and these
motors "on the bench" and am amazed that the total current-drain is less than
an amp for BOTH "1 amp" motors at once! (It's a matter of Power, not just
current, as that is 25 VDC± "chopped", so the instantaneous Power does not
exceed the ExI rating of the motor. Mariss put me straight on that---Duh...)
They work very fine. If you set the jumpers for "x1", you will have to
put-out 2000 pulses per turn from your PC or other controller. If set for
"X10", the motors will make 200 steps/turn, just as they would do with the
"old system" ("pre-Gecko"?). However, each step in this latter case would be
"made up" of ten "microsteps", so the result is less of a "cogging effect".
I am anxious to get this plotter finished so I can get a "feel" for these
G210 "microstepping" drives. SEEMS like will be VASTLY better.

So... If you have not yet written any software (Yes, I do my own with
GWBASIC FOR-NEXT loops and a simple ASM-86 patch to toggle the CW/CCW bits of
the printer-port), you might-well consider using the "X1" jumper setting,
remembering that you will have to ouput 2000 pulses per revolution of a
stepper-motor in that case. This results in "tiny steps"! Which will, then,
require a whole-new "discipline" re acceleration, etc. I can't go there. My
brain is too challenged!

Jan Rowland, Old Troll


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